Shark Files: Ancient 'Supershark' Unearthed in Texas

A mega shark that lived 300 million years ago would have made today's great whites look like shrimps, according to fossils of the beast unearthed in Jacksboro, Texas.

Scientists have dubbed the newfound fossils the "Texas supershark," and the name is fitting: These supersharks were enormous: more than 26 feet (8 meters) long, or more than half the length of a school bus. That's 25 percent larger than the modern great white shark and more than three times as long as other fossil sharks, including the Goodrichthys eskdalensis shark discovered in Scotland and another newfound shark specimen from New Mexico, both of which measure between 6.5 feet and 8.2 feet (2 m and 2.5 m) from head to tail. (Earth's largest shark, C. megalodon, could grow up to 60 feet, or 18 m, long during its heyday, between about 16 million and 2.6 million years ago.)

Supershark lived before the age of the dinosaurs, which emerged about 230 million years ago. Until now, the oldest giant shark was found in rocks dating to 130 million years ago. [8 Weird Things About Sharks]

Supershark's ancient age makes it a prize find, indicating that giant sharks go back much further in the fossil record than previously thought, the researchers said. They presented their unpublished findings today (Oct. 16) at the 75th annual Society of Vertebrate Paleontology conference, in Dallas, Texas.

When supershark was alive, during the Carboniferous period, a shallow sea called the Western Interior Seaway covered Texas and much of the American West. The fossil remains of the sea's marine life are still being uncovered in the ancient seabed, which is how study co-author Robert Williams, of the Dallas Paleontological Society, discovered the supershark fossils, including two fossil braincases. He also found a number of large and pointy, fossilized shark teeth, but it's unclear whether these belonged to the Texas supershark or to another ancient species, the researchers said.

The braincases, which comprise the back end of the sharks' skulls, resemble the corresponding skull parts of other Paleozoic fossil sharks, but "are clearly different from the far shorter" back skull regions of modern sharks, the researchers said.

Shown is a well-preserved fossil of a 300-million-year-old shark from New Mexico. The new "Texas supershark" fossils (not pictured) are less complete, but suggest the supershark was even larger than the New Mexican shark. |
John-Paul Hodnett

To calculate the body size of the supershark without a complete specimen, lead researcher John Maisey, a curator of paleontology at the American Museum of Natural History in New York City, and his colleagues had to get creative.

So they looked to the dimensions of other complete specimens of ancient sharks known as ctenacanthiforms, which are a group of ancient sharks that lived during the Carboniferous period (It's likely supershark is also a ctenacanthiform, but its true identity will emerge only once other supershark remains, such as teeth and fin spines, are found, the researchers said.) The skulls of these ctenacanthiforms accounted for roughly 10 percent of the sharks' entire body length, the researchers found.

If the Texas supershark shared the same proportions, its roughly 31.5-inches-long (80 centimeters) skull suggests that its body was likely more than 26 feet long, Maisey said. The other supershark they discovered likely measured about 18 feet (5.5 m), Maisey said.

Further research is needed to determine whether the Texas supershark specimens represent a known species, such as Glikmanius occidentalis, or a species that has yet to be discovered, Maisey said. But the newly found shark's close relative, the ancient shark from Scotland (Goodrichthys eskdalensis), suggests that this group of sharks had successfully dispersed across large distances. [Dangers in the Deep: 10 Scariest Sea Creatures]

The conference held another gem for shark enthusiasts. During a dig in a New Mexico quarry, John-Paul Hodnett, a graduate student of biology at Saint Joseph's University in Philadelphia, discovered a nearly complete fossilized shark that also dates to about 300 million years ago.

The specimen, a female, measures about 0.6 feet (2 m) long and sports teeth that "are actually brand-new to science," Hodnett told Live Science. "We've never seen this type of tooth before." He plans to analyze the teeth in an upcoming study, he added.

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Shown is a well-preserved fossil of a 300-million-year-old shark from New Mexico. The new "Texas supershark" fossils (not pictured) are less complete, but suggest the supershark was even larger than the New Mexican shark.

Great white sharks are the biggest predatory fish in the world. And despite their mass,
they can travel at ridiculous speeds, at over 35 miles per hour, to track their prey.
Marine biologist Joe Butler traveled with two friends off Hans Bay, South Africa, in hopes of seeing some great whites. Which they did.
See more of Butler's story on a

"In order to bring them in closer, to give everyone a good look, the crew would employ a
tuna head on the end of a long rope and drag it out of the way before the shark had a chance to
grab it," Butler said.

This amazing photo, taken from inside the cage, shows the shark grabbing the bait before anyone had a chance to react.
"There's actually quite a sobering moment when you realize that proverbially you're the
fish out of water, this is their home, and you’re not actually supposed to be there," Butler said.

"I think a lot people have this image in their head of them being sort of an idealistic
predator, but in reality these animals are still quite vulnerable. However, seeing them in their
natural environment is something I would recommend to anyone in a heartbeat."
Above, Butler (left), prepares to cage dive with his two classmates.